Labeling machine with retractable label supports

ABSTRACT

A labeling machine with a rotating label turret which picks up labels from a label magazine and carries the labels past a glue applicator roller and to the label application or on-rolling station includes a plurality of radially movable label supports which are radially extendable and retractable at the periphery of the turret. The retractable label supports include vacuum nozzles connectable to a source of suction. In one embodiment of the invention, the label supports are in the form of spaced ring sectors and the label supports retract if they are not carrying a label to provide clearance between the label support and glue applicator roller to prevent deposition of glue on the label supports. In a modified embodiment of the invention, the label supports are in the form of an array of parallel spaced concentric bands or ribs having a radius of curvature approximately equal to the radius of the outer periphery of the turret. The label supports are biased inwardly by springs and provided with rollers which travel along a fixed, centrally located cam surface which controls the radial position of the label supports. A relieved portion in the cam surface causes the label supports to move radially inwardly at the on-rolling station so that the vacuum pickups and the label support bands are flush or recessed with respect to the periphery of the turret so that uniform pressure can be applied to the full width of the labels and the containers.

1 1 LABELING MACHINE WITH RETRACTABLE LABEL SUPPORTS [75] Inventors: Erich Eder, Neutraubling; Josef Brey, Strucken, both of Germany [73] Assignee: Herman Kronseder, Berliner,

Germany [22] Filed: Jan. 21, 1972 [21] Appl. No; 219,904

I Related U.S. Application Data [63] Continuation of Ser. No. 872,686, Oct. 30, 1969,

abandoned.

[30] Foreign Application Priority Data Oct. 30, 1968 Germany 1806037 [52] U.S. C1. 156/571 [51] Int. Cl. B65c 9/20, B65c 9/22 [58] Field of Search 118/245; 156/566, 567,

[56] References Cited I UNITED STATES PATENTS 1,587,638 6/1926 Feybusch et al 118/245 2,449,298 9/1948 2,773,617 12/1956 3,204,602 9/1965 3,278,359 10/1966 3,322,597 5/1967 3,358,593 12/1967 Ritzerfeld et a1. 3,450,591 6/1969 Zodrow 3,522,134 7/1970 Von Hofe et a1. 3,567,559 3/1971 Dullinger 156/571 FOREIGN PATENTS OR APPLICATIONS 1,169,837 5/1964 Germany 156/571 Feb. 18,1975

Primary Examiner-Benjamin A. Borchelt Assistant Examiner]. V. Doramus Attorney, Agent, or Firm-Wheeler, Morsell, House & Fuller 57] ABSTRACT A labeling machine with a rotating label turret which picks up labels from a label magazine and, carries the labels past a glue applicator roller and to the label application or on-rolling station includes a plurality of radially movable label supports which are radially extendable and retractable at the periphery of the turret. The retractable label supports include vacuum nozzles connectable'to a source of suction. In one embodimentof the invention, the label supports are in the form of spaced ring sectors and the label supports retract if they are not carrying a label to provide clearance between the label support and glue applicator roller to prevent deposition of glue on the label supports. In a modified embodiment of the invention, the label supports are in the form of an array of parallel spaced concentric bands or ribs having a radius of curvature approximately equal to the radius of the outer periphery of the turret. The label supports are biased inwardly by springs and provided] with rollers which travel along a fixed, centrally located cam surface which controls the radial position of the label supports. A relieved portion in the cam surface causes the label supports to move radially inwardly at the onrolling station so that the vacuum pickups and the label support bands are flush or recessed with respect to the periphery of the turret so that uniform pressure can be applied to the full width of the labels and the containers.

11 Claims, 13 Drawing; Figures PATENIED H1 1 8 M 3 as 7. 2 3 3 SHEET 10F 4 Fig. 2

INVENTQRS ids? 9 6f Yray FATENTEB FEB I 8 i975 SHEER 33F a INVENTORS 6' r ga e) Zirqy Fig.9

5y 7 w,z)M, M y W ATTORNEYS LABELING MACHINE WITII RETRACTABLE LABEL SUPPORTS BACKGROUND OF INVENTION This is a continuation of application Ser. No. 872,686 filed Oct. 30, l969, now abandoned.

The invention relates to labeling machines in which labels are received by a label turret from one or more label magazines and carried by suction on the label turret to a glue supplying roller and then to the on rolling station where the glued label is wrapped on a rotating container. Labeling machines of this type conventionally include an arrangement for moving or displacing the gluing roller from a glue applying position adjacent the turret in the event a label is not received from a label magazine to prevent the glue supplying roller from applying glue to the outer surface or periphery of the label turret. If glue is applied to the outer surface of the label turret, the glue will appear on the outer portion of labels and also interfere with transfer of labels from the turret to the containers. The displacement of the glue supplying roller from the normal operating position adjacent the periphery of the rotor is typically accomplished by theuse of a sensor with a feeler arm which will move into a groove in the periphery of the label turret in the absence of a label covering the groove. If a label is not carried by the turret, the feeler actuates a microswitch which energizes a solenoid which pivots and displaces the glue roller from its normal operative position adjacent the labeled turret. Inasmuch as the glue roller has substantial mass, a large solenoid is required to provide the necessary displacement of the glue applicator roller. Since there is a large reaction time for large solenoids, the speed with which the label turret can be rotated has to be limited to 'accommodate the time involved for displacement of and return of the glue roller relative to its operative position. Thus, the output capacity of these prior art labeling machines is limited.

SUMMARY OF INVENTION paratus are eliminated by a machine in which the label turret is provided with a'plurality of circumferentially arranged, radially movable label supports which are provided with vacuum nozzles. The label supports pick up the labels from the label magazine vacuum transfer cylinder and carry the labels to the glue application station and to the on-rolling station.

In one embodiment of the invention, the label sup ports are generally in the form of circular ring sectors which are independently mounted on the label turret for radial movement and together form the periphery of the label turret. The adjacently located label supports are spaced by gaps to permit independent radial movement of each label support. In order to prevent the application of glue to a label support which does not receive a label from the label magazine, an arrangement is provided to move the non-label carrying label support radially inwardly prior to the glue application station. In this regard, the label supports are provided with rollers which are urged against a central fixed cam surface by springs. The cam surface is relieved in the zone of the glue application roller and a label support without a label moves radially inwardly under the influence of the spring and cam to provide clearance between the glue applicator roller and the label support. The absence of a label is sensed by a feeler arm or probe on a microswitch which moves into a groove in the outer face of the label support if the groove is not 'covered by a label. As the feeler arm moves into the groove, the microswitch energizes a motor to move a cam away from the path of a lever pivotally mounted on the label support. If the label support is carrying a label, the motor is not energized and the cam remains in the path of the lever and moves the lever into a position which blocks radial inward movement of the label support. Thus, the label support carrying the label will move the label into contact with the glue applicator roller. Inasmuch as the label completely covers the outer face of the label support, no glue will be applied to the label support itself.

In a modified embodiment of the invention, the label supports are in the form of an assembly of a series of parallel spaced curved bands or ribs which are concentric with the label turret and which are provided with integral vacuum nozzles. The label supports are biased inwardly by springs and moveable radially by a central fixed cam which cooperates with rollers on each of the label supports. When the label supports move radially inwardly under influence of the spring and cam surface, each band in the label support is received in an oblong recess or slot in the outer periphery of the label turret. During the sequence of operation of the label turret, the label supports pick up labels as they pass the label magazines and carry the labels past the glue applicator roller, which is in the form of a series of axially or verti- Cally spaced alternate annular lands and grooves. The lands'receive glue from a glue supply drum and apply a series of spaced horizontal stripes of glue onto the label. The spaced lands interfit in the gaps between the bands on the label support. Thus, if a label support is not carrying a label, the lands containing the glue will rotate in the gaps between the bands and neither the label turrets nor the label will receive any glue. As the supports pass the glue applicator station, the label supports move radially inwardly in the slots due to a recess in the fixed cam surface. Thus, the labels are firmly supported by the surface of the label turret as the turret moves to the on-rolling station where the labels are affixed to the rotating containers which are pressed against the label turret by a resilient pad.

In order to prevent the labels from adhering to the lands on the glue applying roller, both embodiments of the invention can include a guard or fence at the glue application station. The guard includes a series of spaced plates which are staggered with respect to the lands on the glue applying roller and extend into the grooves between the lands. The guard plates have arcuate surfaces concentric with the label supports to permit the labels and label supports to pass with a close clearance. The guard plates prevent the labels from being removed from the label supports and onto the lands of the glue supply roller.

It is an object of the invention to provide a labeling machine with a higher output capacity than the prior art labeling devices.

It is a further object of the invention to provide a labeling machine with a rotating turret provided with a plurality of radially movable label supports which are positioned radially outwardly to engage the glue applicator roller when carrying a label and moved inwardly away from the glue roller when not carrying a label to prevent the application of glue to the label turret.

It is a further object of the invention to provide a labeling machine with a label turret which includes a plurality of spaced radially movable label supports which are positioned radially outwardly to receive and carry the labels to the glue applicator and which are retracted to a position flush with the periphery of the surface of the turret when the label is applied to a container.

Further objects and advantages will become apparent from the following disclosure.

THE DRAWINGS FIG. 1 is a diagrammatic, fragmentary partially broken away plan view of a labeling machine in accordance with the invention.

FIG. 2 is a fragmentary plan view similar to FIG. 1 showing a label support in a retracted position.

FIG. 3 is an enlarged, fragmentary vertical sectional view of the label machine shown in FIG. 1.

FIG. 4 is an enlarged, fragmentary vertical sectional view similar to FIG. 3, in which the label support is not carrying a label.

FIG. 5 is a fragmentary side elevational view of the label support shown in FIGS. 3 and 4.

FIG. 6 is a diagrammatic side elevational view of the glue applicator roller and the label support shown in FIGS. 1 and 2.

FIG. 7 is a plan view of the glue applicator roller and label support shown in FIG. 6.

FIG. 8 is a diagrammatic, fragmentary, partially broken away plan view of a modified embodiment of the labeling machine of the invention.

FIG. 9 is a fragmentary diagrammatic side elevational view of the modified embodiment shown in FIG. 8.

FIG. 10 is a fragmentary diagrammatic plan view of the glue applicator roller and label shown in FIG. 9.

FIG. 11 is a fragmentary perspective view ofa further embodiment of the invention in which the label turret rotates in a direction counter to the label turret shown in FIG. 8.

FIG. 12 is a fragmentary perspective view of the glue applicator station of the invention shown in FIG. 11.

FIG. 13 is a fragmentary perspective view of the onrolling station of the apparatus shown in FIGS. 11 and I2.

DETAILED DESCRIPTION Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structures.

In the drawings, FIG. I shows a labeling machine in accordance with the invention which is generally designated 30 and which includes a plurality of label supports I which are separated from adjacent label supports by gaps 32. The label supports 1 are circumferentially arranged to form the outer periphery of the label turret 34. Means are provided for mounting the label supports 1 on the turret 34 to afford radial movement of the label supports. As disclosed (FIG. 3), the means includes a horizontal disc or plate 18 on the turret 34.

The label supports 1 have upstanding curved wall portions 36 and horizontally extending legs 38 (FIG. 3) which are supported on the upper surface 40 of the disc 18. The upstanding wall portions 36 are generally in the form of circular ring sectors which peripheral surfaces 42. The surfaces 42 are provided with horizontally extending channels of grooves 8 which cooperate with a sensor hereinafter described.

Each label support I is provided with a vertically oriented series of spaced vacuum nozzles 2 (FIG. 5) which communicate with the outer surface 42 of the label supports 1 and are connected to a vacuum manifold 44 (FIG. 3) which is connectable to suction means (not shown). a

In accordance with the invention, means are provided for radially moving the label supports 1 between an extended position (FIGS. I and 3) and a retracted position (FIGS. 2 and 4) which provides clearance between the label support 1 and a glue applicator roller 3 when the label support I is not carrying a label. In the disclosed construction, the means includes a fixed continuous cam surface 14 (FIG. 1) and rollers 13 rotatably connected to the horizontal legs 38 of the label supports 1 and biasing means in the form of springs 15 connected to each of the label supports. The springs 15 maintain the rollers 13 in contact with the cam surface 14.

The invention also provides means operable in response to the absence of a label on a label support to afford inward movement of the label support to the retracted position and operable in response to the presence of a label on the label supports to lock the label supports carrying labels against movement to the retracted position. As disclosed, the means includes a microswitch 10 provided with a feeler arm or sensor 9. The feeler arm 9 is oriented so that it will be received in the groove 8 in the outer face 42 of the label supports 1. The switch 10 is connected by. a circuit (not shown) to a motor 6 provided with a lever 11 connected to the motor output shaft 41. The lever 11 includes a cam 43 (FIGS. 3 and 5). The cam 43 is normally in the position shown in FIG. 3 and is in the path of levers 7 which are respectively pivotally connected to the label supports 1. Normally, the cam 43 causes successive levers 7 to move upward between lugs 12 on the label supports and disc 18 and be clamped there under pressure of springs 15. Thus the label supports 1 are locked against inward displacement as the rollers 13 lose contact with the contoured portion 45 of the cam surface 14.

Inthe event a label support 1 passes the microswitch I0 and the label support isnot carrying a label 5, the feeler arm moves into the uncovered groove 8 and actuates the microswitch 10, which energizes the motor 6 to move the cam 43 away from the path of the lever 7, as shown in FIG. 4. The uncovered label support 1 thus is free to move to the retracted position shown in FIG. 2 under pressure of spring 15, when roller 13 loses contact with relieved or contoured portion 45 of cam 14. This retraction provides clearance between the segment surface 42 and the glue roller 3. Accordingly, the exposed surface 42 does not receive any glue from the glue applicator roller 3.

The use of the motor operated cam 43 affords rapid displacement of the label supports from the extended position to the retracted position and thus the time required in prior art devices to swing the glue applicator roller away from the label turret is eliminated. This arrangement permits a substantial increase in the rotational speed of the turret and the output capacity of the labeling machine.

The invention also provides an arrangement to prevent labels from sticking to the glue roller 3. As disclosed in FIG. 6, the glue applicator roller 3 is provided with a series of annular flanges or lands 50 separated by grooves 22. The lands 50 receive glue from a glue supply drum 4 (FIGS. 1 and 12) as hereinafter described.

The lands 50 apply a series of horizontal spaced stripes of glue on the label 5. To prevent the label from adhering to the lands 50 and being stripped from or shifted on the label supports 1, the invention provides a fence or guard 52 (FIGS. 6 and 7) which includes a vertical stack or array of horizontal fingers or guard plates 19 which are staggered with respect to the lands 50 as shown in FIG. 6 so that the lands 50 extend within the gaps 54 between the guard plates. The guard plates 19 desirably have an arcuate surface 56 adjacent the label supports 1 and concentric with the label supports 1 and label turret 34 to provide a small clearance 57 between the surface 42 of the guard plates 19.

FIG. 8 shows a modified embodiment of the invention in which each label support 60 is in the form of an assembly of parallel spaced horizontal wires, ribs or bands 20. The bands are concentric with the turret 62 and have a radius of curvature approximately the same as the radius ofcurvature of the periphery 66 of the turret 62. Vacuum nozzles 2 are located at the ends of the bands 20. I

The individual bands 20 and vacuum nozzles 2 of each label support are received in spaced oblong recesses or slots 64 in the outer periphery or surface 66 of the turret 62. The bands 20 and vacuum nozzles 2 of each label support 60 are integrally connected by a bracket 67 (FIG. 8). The radial position of the label supports 60 is controlled by a fixed continuous cam surface 14 located centrally of the label supports 60, rollers 13 connected to the brackets 67 on each of the label supports 60 and springs 15 which urge the rollers against the cam surface 14. j

In operation of the modified embodiment of the labeling machine of the invention, the label supports are positioned in their radially outermost position by the cam 14 as the label supports approach the label magazines 17 and label transfer cylinders 16. The vacuum nozzles 2 hold the labels 5 on the label supports 60 which carry the labels to the glue applicator roller 3 (FIG. 9) which applies horizontal stripes of glue on the label 5. As the label supports 60 pass beyond the glue applicator roller 3 in the direction of arrows 69, they are retracted radially inwardly by tension of the springs 15 and cooperation of the rollers 13 with a contour or recess 70 in the cam surface 14 to a position flush with or recessed with respect to the periphery 66 of the turret 62. Thus, when the label supports reach the label application or on-rolling station 72, the label is supported by the surface 66 of the turret 62 rather than the bands 20, thus to provide firm support for the labels 5 as they are applied to the bottles moved by the conveyor 74.

The modified embodiment of the labeling machine shown in FIG. 8 also includes a guard 52 with a stack of horizontal guard plates or stripper fingers 19 which prevent the label from sticking to the lands 50 on the glue applicator roller 3.

As shown in FIG. 9, the bands 20 are in the same plane as the guard plates 19, and are located in registry with the grooves 22 between the lands 50 of the glue roller. Accordingly, the bands 20 of the label supports are staggered with respect to the lands 50 and will not receive any glue from the lands 50 ifno label intervenes between the glue roller 3 and label support, as would be the case if transfer roller 16 failed to transfer a label to the label support.

FIGS. 11, 12 and 13 disclose another embodiment of the labeling machine of the invention similar to FIGS. 8, 9 and 10, but in which the turret rotates in a direction counter to the direction of rotation of turret 66 shown in FIG. 8.

Referring to FIG. 11, a label magazine 17 is shown with a supply of vertically-stacked labels 5. FIG. 11 also shows a vacuum actuated label transfer cylinder 16 carrying a label 5 to the label support 60. The bands 20 of the label supports are received in narrow channels or recesses 81 in the face 82 of the label turret 80. The vacuum nozzles 84 are received in rectangular apertures or recesses 86 in the turret face 82.

FIG. 12 shows the glue application station with a glue supply cylinder or drum 4 which receives glue from a glue supply hose or conduit 87. An adjustable wiper blade mechanism 90 controls the thickness of the film or glue on the outer surface of the cylinder 4. As the drum 4 and roller 3 rotate, the glue is transferred to the glue applicator roller 3. The lands 50 on the roller 3 apply the glue to the labels 5 in the form of narrow horizontal stripes. FIG. 12 also shows the guard 52 with staggered guard plates 19.

FIG. 13 shows the label application or on-rolling station 94 in which the bottles move in the direction shown by arrow 98. The label turret rotates in the direction shown by arrow 100. The bottles or containers 102 are firmly pressed and rolled against the turret face and the intervening labels 5 by a resilient stationary pad 104, which causes the bottles to rotate in the direction shown by arrows 106. At this station the label support 60 is in its retracted position. Thus the full surface 82 of theturret 62 is utilized to press and roll the label 5 onto containers 102.

In all embodiments of the invention, the glue roller 3 is mounted on a fixed stationary axis. Avoidance of transfer of glue from the roller to the label support is accomplished by means other than swinging the glue roller away from the label support. Accordingly, the machine is adapted for considerably higher output than heretofore achieved.

What is claimed is:

1. In a labeling machine which includes a rotatable label turret, a label magazine for supplying labels to the turret, and a glue applicator roller located adjacent the periphery of said turret, the improvement comprising a plurality of label supports around the periphery of said turret, means for mounting said label supports on said turret for radial movement with respect to the axis of said turret, means for radially moving said label supports between extended and retracted positions, said means for radially moving said label supports including rollers on each of said label supports, a fixed cam surface and springs biasing said rollers against said cam surface, said cam surface being contoured adjacent said glue applicator roller, and means operable in re sponse to the absence of a label on said label supports to afford inward movement of said label supports to the retracted position to provide clearance between said label supports and said glue applicator roller, and operable in response to the presence of a label on said label supports to lock label supports carrying labels against movement to the retracted position when said label support is adjacent said relieved cam surface.

2. The improvement of claim 1 wherein each of said label supports includes a vacuum nozzle.

3. The improvement of claim 1 wherein said label supports include label support portions in the form of circular ring sectors," said label supports being separated by gaps and together forming the periphery of said turret.

4. Alabeling machine comprising a label turret, a label magazine located adjacent the periphery of said label turret, a glue applicator located adjacent said turret, a label application station, said turret having a peripheral surface with a series of recesses, a corresponding series of label support bands disposed in said recesses, means interconnecting said bands for concurrent movement of said bands between an advanced position in which they extend beyond the peripheral surface of the turret for receiving labels from said label magazine and receiving glue on the labels from said glue applicator and a retracted position at said label application station flush with said peripheral surface of said turret in which position the labels are supported at least in part by said peripheral surface of the turret.

5. The labeling machine of claim 4 in which each of said bands includes a vacuum nozzle.

6. The labeling machine of claim 4 in which the means for moving the bands comprises a cam track, a cam follower roller and spring means biasing the roller against the track, said track having a profile which projects the bands into their advanced position adjacent the label magazine and glue applicator and retracts the bands adjacent the label application station.

7. In an installation for applying gummed labels to bottles and the like; comprising transfer cylinder means rotatable about a fixed axis to receive successive gumfree labels at a first station and to successively deliver received labels to a second station spaced from the first station for gumming the labels, said transfer cylinder means including a plurality of segments each having an exposed surface for transporting a label in contact therewith between said stations and for holding labels in contact with gum-applying means at the second station, support means rotatable about said fixed axis including means to mount said segments for movement between a normal position at said second station to apply gum to a label and a retracted position spaced away from the gum-applying means, and sensing means responsive to the absence of a label on a segment after the segment has moved from the first station to move that segment to the retracted position before said exposed surface reaches the second station, the exposed surface of each of said segments being provided with a recessed portion, said recessed portion being covered when a label is positioned on the surface, said sensing means including a movable feeler element normally biased to enter said recessed portion at a location between the first and second stations.

8. An installation according to claim 7 wherein said exposed surfaces of the segments when in said normal positions define segments of a cylinder of revolution concentric with said fixed axis, and said segments are mounted for generally radial inward movement to said retracted position, said recessed portions of the exposed surfaces thereof comprising circumferentially aligned annular grooves.

9. An installation according to claim 8 wherein all of the segments are substantially identical.

10. An installation according to claim 7 wherein said means to mount said segments for movement includes camming means having a plurality of elements including a cam member and a cam follower roller to retract a segment in the absence of a label, one of said elements being mounted on each of said segments, another of the elements being positioned in coacting relationship between the first and second stations.

11. An installation according to claim 10 wherein said cam element is 'mounted adjacent the path of 'movement of said segments, each of said segments including a cam follower roller mounted for movement between an inoperative position and an operative position for coacting engagement with the cam member to retract the respective segment. 

1. In a labeling machine which includes a rotatable label turret, a label magazine for supplying labels to the turret, and a glue applicator roller located adjacent the periphery of said turret, the improvement comprising a plurality of label supports around the periphery of said turret, means for mounting said label supports on said turret for radial movement with respect to the axis of said turret, means for radially moving said label supports between extended and retracted positions, said means for radially moving said label supports including rollers on each of said label supports, a fixed cam surface and springs biasing said rollers against said cam surface, said cam surface being contoured adjacent said glue applicator roller, and means operable in response to the absence of a label on said label supports to afford inward movement of said label supports to the retracted position to provide clearance between said label supports and said glue applicator roller, and operable in response to the presence of a label on said label supports to lock label supports carrying labels against movement to the retracted position when said label support is adjacent said relieved cam surface.
 2. The improvement of claim 1 wherein each of said label supports includes a vacuum nozzle.
 3. The improvement of claim 1 wherein said label supports include label support portions in the form of circular ring sectors, said label supports being separated by gaps and together forming the periphery of said turret.
 4. A labeling machine comprising a label turret, a label magazine located adjacent the periphery of said label turret, a glue applicator located adjacent said turret, a label application station, said turret having a peripheral surface with a series of recesses, a corresponding series of label support bands disposed in said recesses, means interconnecting said bands for concurrent movement of said bands between an advanced position in which they extend beyond the peripheral surface of the turret for receiving labels from said label magazine and receiving glue on the labels from said glue applicator and a retracted position at said label appLication station flush with said peripheral surface of said turret in which position the labels are supported at least in part by said peripheral surface of the turret.
 5. The labeling machine of claim 4 in which each of said bands includes a vacuum nozzle.
 6. The labeling machine of claim 4 in which the means for moving the bands comprises a cam track, a cam follower roller and spring means biasing the roller against the track, said track having a profile which projects the bands into their advanced position adjacent the label magazine and glue applicator and retracts the bands adjacent the label application station.
 7. In an installation for applying gummed labels to bottles and the like; comprising transfer cylinder means rotatable about a fixed axis to receive successive gum-free labels at a first station and to successively deliver received labels to a second station spaced from the first station for gumming the labels, said transfer cylinder means including a plurality of segments each having an exposed surface for transporting a label in contact therewith between said stations and for holding labels in contact with gum-applying means at the second station, support means rotatable about said fixed axis including means to mount said segments for movement between a normal position at said second station to apply gum to a label and a retracted position spaced away from the gum-applying means, and sensing means responsive to the absence of a label on a segment after the segment has moved from the first station to move that segment to the retracted position before said exposed surface reaches the second station, the exposed surface of each of said segments being provided with a recessed portion, said recessed portion being covered when a label is positioned on the surface, said sensing means including a movable feeler element normally biased to enter said recessed portion at a location between the first and second stations.
 8. An installation according to claim 7 wherein said exposed surfaces of the segments when in said normal positions define segments of a cylinder of revolution concentric with said fixed axis, and said segments are mounted for generally radial inward movement to said retracted position, said recessed portions of the exposed surfaces thereof comprising circumferentially aligned annular grooves.
 9. An installation according to claim 8 wherein all of the segments are substantially identical.
 10. An installation according to claim 7 wherein said means to mount said segments for movement includes camming means having a plurality of elements including a cam member and a cam follower roller to retract a segment in the absence of a label, one of said elements being mounted on each of said segments, another of the elements being positioned in coacting relationship between the first and second stations.
 11. An installation according to claim 10 wherein said cam element is mounted adjacent the path of movement of said segments, each of said segments including a cam follower roller mounted for movement between an inoperative position and an operative position for coacting engagement with the cam member to retract the respective segment. 